TWI437511B - Metallic composite coins with modulated electromagnetics signatures - Google Patents

Description

Metal composite coin with modulated electromagnetic characteristics

The present invention is directed to novel metal composites that are suitable as coinage materials for the foundry industry. More particularly, the present invention is directed to metal composite materials designed for the specific purpose of affecting their electromagnetic properties, particularly their electromagnetic signature (EMS), and includes a method of making coins and the coins themselves. .

Coins are often used as a payment tool for vending machines or similar automated machines. Under this function, the coin needs to be recognized and recognized by the machine and accept or reject the coin. This discriminating procedure is carried out in a device called a coin acceptor and, in general, it contains various physical properties of the coin as it passes through the mechanism of the receiver.

Most coin acceptors currently in use rely on signals caused by a coin disturbing a variable electromagnetic field. For example, a coin moves between two coils, which serve as a radiation antenna and a receiving antenna, respectively. Next, the signal obtained by the receiving coil is analyzed using a proprietary algorithm to produce an electromagnetic signature (EMS) called the coin. Based on the EMS of the coin, it may be decided to accept or reject the coin.

One of the common problems affecting coin acceptors is due to the fact that the electromagnetic characteristics (EMS) of different coins may be very similar. Fraud may occur when coins of different denominations or coins issued by different jurisdictions have similar EMS values.

With reference to the above, the EMS value is not calculated in any physical, chemical or mathematical formula. Rather, it is a set of numbers produced by the software and algorithms designed by each coin acceptor mechanism manufacturer. EMS is unitless and is established in a set of shapes that determine the diameter, edge thickness, weight, alloy composition, and the like of a coin at different frequencies. Moreover, the value is not a single repetition value that identifies the characteristics of the coin. The values are not exact; they vary with different coins within a certain range. Therefore, this range is extremely important to coin acceptor manufacturers because even fully valid coins may be rejected. Therefore, the range of values must be established to properly characterize the particular characteristics that identify the particular features of a coin, such as its diameter, edge thickness, or alloy.

Perhaps one of the best ways to relate an EMS to a known physical measurement is via the conductivity of the metal. Available commercially available devices measure conductivity, such as: Dr. Foerster's ^TM Sigma D Conductivity Meter and Fischer Sigmascope SMP10 conductivity meter.

As the price of base metals has risen in the last three decades, people in the foundry industry have had some ideas on how to reduce the cost of making coins, including finding metal substitutes for more expensive base metals such as nickel and copper. Alternatives include mono-ply plated steel products. Single layer steel plating consists of plating a single layer of metal or an alloy on the steel. This is in contrast to multi-ply plated steel, which consists of several layers plated on steel.

Sample patent applications and patents describing single-layer steel plating include: Canadian Patent Application No. 2, 137, 096, Canadian Patent Application No. 2, 271, 654, U.S. Patent Application Serial No. 4, 089, 753, U.S. Patent Application Serial No. 4, 247, 374, and U.S. Patent Application Serial No. No. 4,279,968. Other options include the core in the coin being made of a metal such as nickel or copper with a single layer plated with another metal or an alloy. Sample patents of this type include: U.S. Patent Application Serial No. 3,753,669, U.S. Patent Application Serial No. 4,330,599, and U.S. Patent Application Serial No. 4,599,270.

Inconveniently, the coin acceptor mechanism of the vending industry generally does not distinguish between coins made of the same alloy and having approximately the same diameter, thickness and weight in different countries. In addition, single-layer steel-plated coins have very variable EMS values and are very close to the EMS value of steel, so many vending machines cannot be calibrated to distinguish between normal steel and single-layer steel plating.

Metal discs (especially coins) that have been produced are distinguished and separated from another metal disc according to their magnetic properties. As proposed in German Patent Application No. DE 3207822 and U.S. Patent No. 3,634,890, laminated metal coatings suitable for coin production include: magnetizable metals (like: nickel) and non-magnetizable metals (like: inclusion) A copper-nickel alloy of 5 to 60 percent nickel). No. 4,973,524 describes a method of making a coin suitable as an alternative to a nickel-containing coin, the method comprising the steps of: forming a laminated composite comprising a first resist One of the core layers of steel, such as: ferritic-chromium steel, and several layers coated with a second resist steel on the opposite side of the core layer, such as: Vostian nickel-chromium steel (austenitic Nickel-chromium steel).

Despite the above methods, fraudulent counterfeiters are actively looking for ways to use such electronic devices used in vending machines, so fraud is still a major problem. Therefore, there is still a need for a new type of coin that combines the metal of the maker of legal tender but can be distinguished by its EMS value.

The present invention seeks to meet this need and related needs.

When the vending machine cannot distinguish between coins from two different countries, or when the vending machines cannot distinguish between a single layer of plated steel coins and a steel sheet, the shortcomings of the current coin technology can result in a safety and profit. damage. In order not to jeopardize the vending machine industry, many coin acceptors simply do not accept any single layer of plated steel coins.

The present invention provides an alternative to currently available coin material. In particular, the present invention relates to novel multilayer metal composites and their use in coin making.

In the case where the core steel is made of another magnetic material such as nickel and one or more of the plating layers are non-magnetic, or if the core is non-magnetic, the plating is magnetic In the case of materials, the intensity of the induced current can be adjusted by controlling the thickness of the layers of the paired combination of magnetic and non-magnetic materials. In this manner, the coin will produce completely different induced current characteristics. This allows the coin acceptor mechanism to distinguish, identify, and identify different coins, even coins of the same or a similar diameter, thickness, and weight. The ability to identify two coins with the same physical characteristics even with different designs is a unique and very powerful tool for controlling the misuse of coins in one country in another. Unlike humans, the coin acceptor mechanism in the state of the art does not observe such visual or graphical features of the coin to identify the coin. As noted above, the receiver mechanism acts on the current waveform data and the defined feature points.

It has been found that by wisely selecting the type of metal deposited by electroplating (electroplating) and by manipulating the thickness of the plating deposit of the metal layers, the type of induced current produced by a coin can be adjusted. If one or more of the electroplated layers are non-magnetic and the core is made of a magnetic material (such as steel or nickel), the intensity of the induced current can be adjusted. Alternatively, if one or more layers are magnetic and the core is made of a non-magnetic material (such as: copper, zinc, tin, aluminum, silver, gold, indium, brass or bronze), the induction can also be adjusted. The strength of the current. In particular, by controlling the thickness of the pair of magnetic and non-magnetic materials, the coin will produce a completely different induced current, which in turn allows the coin acceptor mechanism to distinguish coins, even if they have the same diameter, Thickness, or have the same or similar weight.

It has been found that single layer plating (especially with magnetic metals such as nickel and cobalt) has inherent limitations that make it difficult to manipulate the EMS of a coin, even to correct the thickness of the coin. And other features to manipulate.

According to the above, the present invention provides:

1) A multilayer plating process for fabricating metal composites that overcomes the inability to distinguish between two coins containing the same alloy and having the same size;

2) A multilayer plating process for the manufacture of metal composites that overcomes the infeasibility and difficulty of accurately correcting a vending machine to identify a single layer of plated steel coin, particularly when the plating material is magnetic, such as: nickel or cobalt.

3) a multilayer plating process that prevents counterfeiting of coins made of electroplated material because the order of the metallized layers and the plating thickness of the layers can be defined and controlled in a reproducible manner to The coin produces the same induced current, the same EMS.

4) A multilayer plating process for fabricating a metal composite, wherein the core may be steel, nickel and then a non-magnetic metal (such as: copper, or brass, or bronze) may be deposited as a layer on the steel Pairing, and the EMS is controlled by defining the thickness of the deposited metal layers.

Alternatively, the magnetic and non-magnetic pairing can be electroplated in the reverse order, ie copper is on top of the steel, followed by nickel. This key is in controlling the thickness of the layers of deposited metal.

5) A multilayer plating process in which (1) a magnetic metal such as nickel or cobalt is plated on a magnetic steel core, and then (2) a non-magnetic metal is deposited, such as (but not limited to): copper, yellow Copper, bronze or zinc, and (3) electroplating an outer nickel layer to control the electromagnetic signal of the metal composite product. This is achieved by controlling the thickness of the deposited metals. The outer nickel layer may be any other metal for visual color effects and/or wear resistance, which may be magnetic (like: chrome) or non-magnetic.

6) A multilayer plating process in which a magnetic metal such as nickel or cobalt is deposited on a core of a non-magnetic metal (such as copper, brass or bronze) to form a pair of magnetic and non-magnetic metals to control the EMS value. This is achieved by controlling the thickness of the deposited nickel or cobalt.

7) A multilayer plating process in which (1) a magnetic metal such as nickel is deposited on a steel core, followed by (2) deposition of a non-magnetic metal such as copper, zinc, brass, bronze, and (3) ) deposit another layer of magnetic metal, like nickel. A final layer of silver or gold is deposited to control the electromagnetic signal of the composite product. This is achieved by controlling the thickness of the deposited metals. In addition to the first pair of magnetic-nonmagnetic combinations (nickel-copper), the outer layer of silver or gold is deposited to provide a valued appearance and to modify the composite product portfolio (nickel-silver or nickel-gold) Conductivity or color.

The other objects, advantages and features of the present invention will become more apparent from the description of the appended claims.

All coin acceptors are designed to operate on the principle of induction. A coin acceptor is designed to have energized coils (sensors) with power at 2 or 3 different frequencies, typically 2 frequencies, high frequency (240 KHz and higher) and low frequency (60 KHz and lower). The coils are sufficiently spaced from each other that there is no significant current that can be measured by a current analyzer connected to one of the energized coils.

When a coin is thrown into a coin acceptor, the (space) gap between the coins will quickly and temporarily close, and cause a current as the coin passes through the coils (sensors). The induction of the sensors combined with the eddy currents in the coin produces two (2) sinusoidal currents due to two (2) different sets of coils at two (2) different frequencies.

The current analyzer combines the two currents and then analyzes the currents at various points identified as EMS signals.

These extracted EMS values are analyzed with specific algorithms specific to each coin acceptor model and brand. These EMS values are converted into data identified as parameters.

The EMS values are based on the size (diameter), mass (edge thickness and weight) and the type of metal (or alloy) used to make the coins.

Therefore, the coin acceptor cannot distinguish coins of the same alloy and approximately the same diameter. For example, five (5) cents in the US and five (5) cents in Canada before 1999 are made of cupronickel (75% copper 25% nickel) and cannot be used in existing coin acceptors in the market. the difference.

These shortcomings of today's coin identification and identification techniques can have serious economic consequences for a country. In the case of the US (5) and Canadian (5) cent coins, this problem is acceptable because their face values are roughly the same. However, for other countries, if the foreign exchange rates vary widely, these economic differences may be quite serious, because if the coins in the two countries have full or nearly the same diameter, size, thickness, weight and/or the same Alloys, these coins can be exchanged for use in vending machines. This opens the door to fraud and forgery because the vending machine sensors do not rely on such images or visual designs to identify and distinguish the coins.

The object of the present invention is to manufacture metal composite materials suitable for use in coin production. These formed coinage products are unique in that they help to eliminate such problems that are plaguing many similar coins outside the European, North American and Asian economies. Many countries have a number of automated sales services that rely on coin use, including: automatic candy machines, sandwich makers, phones, non-alcoholic beverage dispensers, coffee machines, public or public transportation services, parking meters, road tolls, casinos and games. machine. The new type of coin of the present invention should be extremely useful for such services.

Since the coin acceptor has different tools and means for capturing and recording the EMS values, the best way to illustrate and explain the concept is to relate the metal properties to their current conductivity, which is IACS%. Measurement (international annealed copper standard percentage).

Figure 1 shows this typical conductivity of different alloys at different frequencies. The coin identification code (coin No. 1 to coin No. 80) is displayed on the X-axis, and the metal conductivity measured at IACS% is displayed on the Y-axis. Such a measuring system using Dr.Foerster's ^TM measured conductivity meter at different frequencies.

Figure 1 shows that each metal product (for example, white copper or stainless steel) has its own conductivity at a fixed frequency. The product identified as RCM (Royal Royal Mint) Nickel-Copper-Nickel Ni-Cu-Ni (5-15-5) contains one of a low carbon steel core (SAE 1006) coated with a 5 micron layer. Nickel is then plated with a layer of 15 micron copper and finally a layer of 5 micron nickel.

Figure 2 shows the difference between a single layer blank and an RCM multilayer blank. An electroplating procedure suitable for the purposes of the present invention is described in U.S. Patent No. 5,139,886 and U.S. Patent No. 5,151,167. All of these patents are incorporated herein by reference.

Returning now to Figure 1, the RCM multilayer blanks (7.5-20-7.5) show a small range of conductivity values at 60 kHz, which is between 20 and 28 IACS%. Remind the X axis to indicate the same coin code. Each coin code has an IACS% value at a frequency. For example, coin 4 has a value of 24 IACS% and coin 7 has a value of 22 IACS%. This small difference is extremely difficult due to the precise thickness of the electroplated nickel deposition and copper deposition, as the deposition is accomplished by electroplating, which is well known to those skilled in the art. This plating deposit is slightly different between coins and coins.

Figure 1 also shows that the RCM nickel-copper-nickel (15-2-15) product has a different range of conductivity. It is plated with 15 micron nickel, 2 micron copper, and 15 micron nickel.

Figure 3 shows the EMS values for steel, special multilayer nickel-copper-nickel RCM plating and white copper at 60 kHz.

A comparison of the EMS values of a single layer of nickel on steel results in an EMS value of about 110% IACS at 60 kHz, which is about the EMS value of the steel. The range of values reflects the strong magnetic properties of steel and nickel. In fact, such variations in the associated single layer product are so great that the vending machine manufacturer does not consider the coin acceptor used to correct it. In addition, steel cannot be considered as a coin material because of the following reasons: steel rust, steel is a very common material and if a coin is made only of steel, any person with equipment can cut one of the correct dimensions. Steel plates are quickly forged.

As noted above, steel and nickel are magnetic and nickel plated steel is also magnetic. In order to make a metal alloy less magnetic and to provide a more stable EMS signal that can be used within the range designed by the vending machine manufacturer, we must stabilize the EMS value in the vending industry. Within a narrow range.

An electroplating material that substantially affects the current conductivity of a coin and that can be altered by modifying the thickness of the material provides a means for controlling and varying the conductivity and thereby changing the EMS values of the coin. Furthermore, if a metal eliminates these magnetic effects, the degree of magnetic properties can be varied and thus the EMS value can be adjusted.

Pure copper is very conductive, it has very low resistance to current supply and it is non-magnetic. Other metals or alloys used to make coins may be considered (but not limited to): aluminum, zinc, tin, silver, gold, indium, brass, and bronze.

When a non-magnetic metal is plated on the steel, the total magnetic value of the paired "non-magnetic metal-steel" combination can be changed. This adjustment of the magnetic strength of a metal composite is an important consideration that allows for elastic changes in the EMS values of the metals formed. Furthermore, by varying the deposited thickness of the non-magnetic metal layer on the steel, the bonded non-magnetic-steel can be given a variety of different magnetic degrees. These important findings provide an effective tool to control the EMS values of the coins to avoid fraud.

In addition, the conductivity can greatly affect the strength of the current through the non-magnetic-steel pairing. In other words, the EMS value of the coin can be controlled by judiciously selecting the thickness of the metal or alloy deposited on the steel, or the thickness of the combination of metals or alloys. For example, by combining metals such as copper, nickel and steel, it is advantageous to combine the magnetic and electrical properties of the metals to change the EMS values of the finished coins to provide a specific range for each type of coin. Values, the coin acceptor can use these specific values to identify, distinguish, distinguish, and finally decide to accept or reject the coins.

Example 1

To illustrate the control applied to the electromagnetic signals of the coins of the present invention, a series of plating experiments are performed below. Nickel and copper are alternately deposited on the steel blank to produce different thicknesses. The conductivity of the combined effect of the layers of nickel and copper was measured at different frequencies, with different results as expected.

Figure 4 illustrates the difference in electromagnetic properties of the metal caused by the combination of nickel and copper layers. In particular, this figure shows the electrical resistance of the multilayer electroplated blanks as the degree of copper content changes while the nickel layers remain constant. The X axis shows the coin blank code and the Y axis shows the resistance of the coins measured at 60 kHz as a Dr. Foerster conductivity meter.

Each layer has a specific effect on the EMS value of the coins. Different metals have different effects. Tests have shown that changes in the thickness of the copper layer have the greatest effect on the EMS value.

The trend of this change in conductivity in Figure 4 is very clear. On average, Multi 2 (7-14-7) with 14 micron copper has a lower resistance than Multi 3 (7-12-7) with 12 micron copper. Multi 1 (7-20-7) with 20 micron copper has the lowest average resistance.

Example 2

In another set of experiments, the EMS values for a large number of coins were recorded. The coins plated by a multilayer plating process such as that described in Canadian Patent No. 2,019,568 (Truong et al.) may be passed through a commercial coin sorter Scan Coin 4000 (Fig. 5). The recorded values identified by IC1 (internal conductivity on coil 1) are plotted against copper thickness by measuring the cross-section of the coins, inlaying the coins for metallographic observation, and optical The thicknesses of the different layers of copper and nickel in the coins are measured.

The inner nickel layer is fairly consistently 6 microns and the outer nickel layer is between about 10 and 11.5 microns. The copper layer varies between 4 and 24 microns.

Figure 5 shows the copper thickness and a direct dependence between the IC1 values recorded by the Scan Coin classifier.

Example 3

In another series of experiments, three (3) different types of blanks were electroplated with the following plating thickness conditions:

The blanks are cast into coins and the coins pass through the commercial ScanCoin coin sorter (model 4000), which measures the conductivity of the coins.

Figure 6 shows this conductivity analysis where the X-axis shows the number and the Y-axis shows the conductivity values of all three samples. These three representations (on the right hand side of Figure 6) are typical bell curve distributions of the same data for the three types of blanks. Again, it can be observed that when changing the thickness of the copper layer, the conductivity of the coins is also altered, and such differences allow the coin reader of the ScanCoin coin sorter to distinguish, identify and classify the coins.

We should note that the weight difference between the three coins is not perceptible for all practical purposes, as some micron differences in copper are within the range of 0.005 grams to 0.01 grams.

The present invention thus provides a powerful tool for changing the EMS value of a coin. Since the program can change the conductivity of metal coins, which is not possible with conventional metallurgical alloys, the program is unique.

The practical use of the present invention is significant because it provides tools to alter the physical and electrical properties of the coin without substantially altering the alloy composition. The program is unique, extremely economical and provides an excellent way to make different electromagnetic signals for coin differentiation, which other tools cannot.

Each alloy has its own EMS. A small change in the composition of the alloy of more than one percent does not change the EMS value of the alloy. In multilayer plating, the EMS value of the metal product can be substantially altered by judiciously changing the size of some of the micron in the copper layer deposition and causing the coin weight to be less than 0.005 percent.

This concept applies to the deposition of two or more layers of metal, at least one of which is non-magnetic, such as: copper, zinc, tin, aluminum, silver, gold, indium, brass or bronze.

The above-described specific embodiments of the present invention are for illustrative purposes only. Variations, changes and modifications of the specific embodiments described herein may be made without departing from the scope of the invention as defined by the appended claims.

Figure 1: Conductivity of different metal composites.

Figure 2: Electroplating procedure (A) Single-layer technology with a metal coating on a steel blank, such as: nickel coated on steel to make white coins, copper coated on steel to make red coins and bronze or brass coated Made of yellow coins on steel; (B) The Royal Canadian Mint (RCM) multi-layer technology uses more than one coat, for example: in the case of red and yellow coins, nickel is coated on steel and recoated Upper copper, bronze or brass, depending on the color selected for the coin; and (C) in one embodiment, the RCM multilayer technique uses three layers to make white coins, wherein the first layer is nickel, The second layer of copper and the third layer are nickel plated on the copper which forms a layer of sandwiches.

Figure 3: EMS values for different metal composites at 60 kHz.

Figure 4: Copper layer and EMS value of the electroplated blank.

Figure 5: Dependence between copper thickness and internal conductivity 1 (IC1).

Figure 6: Conductivity analysis of IC1 in quantitative terms.

Claims (14)

A metal composite coin having modulated electromagnetic characteristics, comprising: a core layer and at least two other layers plated on the core layer, wherein at least one of the layers is made of a non-magnetic metal or alloy, And at least one of the layers is made of a magnetic metal or alloy having a thickness selected according to their electromagnetic properties. The metal composite coin according to claim 1, wherein: the core layer is composed of a magnetic metal or an alloy; and one of the at least two other layers is an intermediate layer, and the intermediate layer is plated on the core layer. One of the upper magnetic metal or alloy composition; and the other of the at least two other layers is an outer layer composed of a non-magnetic metal or alloy electroplated on the intermediate layer. The metal composite coin of claim 2, further comprising a magnetic metal or alloy electroplated on the outer layer to form a fourth layer. The metal composite coin of claim 3, further comprising a non-magnetic metal or alloy electroplated on the fourth layer to form a fifth layer. A metal composite coin as described in claim 2, further comprising A non-magnetic metal or alloy is electroplated on the outer layer to form a fourth layer. The metal composite coin of claim 5, further comprising a magnetic metal or alloy electroplated on the fourth layer to form a fifth layer. The metal composite coin according to claim 1, wherein: the core layer is composed of a magnetic metal or an alloy; and one of the at least two other layers is an intermediate layer, and the intermediate layer is plated on the core layer. One of the upper non-magnetic metals or alloys; and the other of the at least two other layers is an outer layer composed of a magnetic metal or alloy electroplated on the intermediate layer. The metal composite coin of claim 7, further comprising a magnetic metal or alloy electroplated on the outer layer to form a fourth layer. The metal composite coin of claim 8, further comprising a non-magnetic metal or alloy electroplated on the fourth layer to form a fifth layer. The metal composite coin of claim 7, further comprising a non-magnetic metal or alloy electroplated on the outer layer to form a The fourth layer. The metal composite coin of claim 10, further comprising a magnetic metal or alloy electroplated on the fourth layer to form a fifth layer. The metal composite coin of claim 1, wherein the magnetic metal or alloy is selected from the group consisting of: nickel, cobalt, chromium, stainless steel, and Worth-fertilizer steel (austenitic) -ferritic steel). The metal composite coin according to claim 1, wherein the non-magnetic metal or alloy is selected from the group consisting of: copper, zinc, tin, aluminum, silver, gold, indium, brass, and bronze. The metal composite coin according to claim 1, wherein the magnetic metal or alloy is nickel, chromium, steel or Worth-fertilizer steel, and the non-magnetic metal or alloy is copper, zinc, tin, aluminum, Silver, gold, indium, brass or bronze.